This invention relates generally to a borescope or endoscope for providing full color video images of inaccessible objects of the type having a cable actuated hollow steering section, and more particularly, to a compact portable battery operated borescope system.
A borescope is generally characterized as an elongated flexible insertion tube with a viewing head at its distal end and a control and processing section at its proximal end. Various devices have been provided in the prior art for realizing a full color video picture of a target situated within a remote cavity. These devices have been gradually improved over time to where today, most devices of this type employ an external light source conveyed to the image viewing head by fiber optic bundles, together with a solid state image sensor and lens system positioned in the distal end of the insertion tube of the borescope connected to an external video processing system and standard television format display equipment.
Endoscope/borescope systems of this general type have been disclosed in various patents owned by a common assignee of the present applicant, such as U.S. Pat. No. 4,253,447 to Moore et al. U.S. Pat. No. 4,261,344 to Moore et al. U.S. Pat. No. 4,491,865 to Dana et al., to mention a few. The disclosure of U.S. Pat. No. 4,491,865 is hereby incorporated by reference as background in understanding the present invention. Another early endoscope system is shown in U.S. Pat. No. 4,621,618, to Omargi, which describes a central control/display station, separate light system, and a drive body for the insertable endoscope portion. The central control has a joystick actuated motor drive circuit for the wire controlled bendable section of the insertion tube. This rather large cumbersome system requires a paramedic to handle the endoscope while the doctor operates the device from the control station. Also, the apparatus obviously is not portable.
Applicant, on the other hand, has provided a compact automatic system that can easily be operated and controlled by one person. The major functions of illumination of the object, video image pick-up, video processing, and video display are automatically accomplished. The bendable section of the insertion tube is actuated by movement of a small joystick control electrically connected to a servo motor, allowing the joystick control to be selectively located at any convenient point with respect to the rest of the apparatus or the object being viewed. As applications for systems of this type have expanded from purely medical applications to wide ranging industrial applications, the need for portable compact systems that can be easily transported to remote locations and operated without immediate access to commercial power has required extensive changes and modifications to the earlier types of systems, and resulted in a number of significant improvements in capabilities from both the physical size and the electronic processing viewpoints.
For instance, inspecting jet engines has become increasingly important. Specialized borescopes having extreme flexibility and portability have been required to allow use on open flight lines where power is not readily accessible and for accessing difficult remote portions of an engine necessitating very accurate and careful manipulation of the viewing head of the insertion tube. These requirements have placed stringent demands on the articulation systems of borescopes as well as on the packaging and power consumption of the lighting, control, and electronic processing portions of the systems. At the same time, requirements for improved capability have increased and it has become necessary to provide greater illumination capabilities to permit resolution of smaller and smaller defects at greater and greater distances from the viewing head.